针对阻尼结构设计,利用拓扑优化技术研究了阻尼结构模态损耗因子最大化设计问题。采用密度法(Pseudo-density Method)和材料属性合理近似模型(Rational Approximation of Material Properties,RAMP)建立了以阻尼材料用量为约束条件、模...针对阻尼结构设计,利用拓扑优化技术研究了阻尼结构模态损耗因子最大化设计问题。采用密度法(Pseudo-density Method)和材料属性合理近似模型(Rational Approximation of Material Properties,RAMP)建立了以阻尼材料用量为约束条件、模态损耗因子最大化的阻尼板结构拓扑优化数学模型,并进行了灵敏度分析;利用优化准则法(Optimality criteria,OC),给出了阻尼结构拓扑优化设计方法和流程,得到了在一定阻尼材料用量下阻尼板结构的模态损耗因子最大的阻尼材料最优分布构形。相关算例结果表明该方法适合于阻尼结构的优化设计或轻量化设计。展开更多
The wide application of evaporative cooling techniques in which the optimization criteria form the theoretical basis for improving evaporative cooling performance is essential for energy conservation and emission redu...The wide application of evaporative cooling techniques in which the optimization criteria form the theoretical basis for improving evaporative cooling performance is essential for energy conservation and emission reduction.Based on exergy analysis and the entransy dissipation-based thermal resistance method,this contribution aims to investigate the effects of flow and area distributions in the optimization of the performance of indirect evaporative cooling systems.We first establish the relationships of exergy efficiency,entransy dissipation-based thermal resistance and cooling capacity of a typical indirect cooling system.Using the prescribed inlet parameters,the heat and mass transfer coefficients and the circulating water mass flow rate,we then numerically validate that when the cooling capacity reaches a maximum,the entransy dissipation-based thermal resistance falls to a minimum while the exergy efficiency is not at an extreme value.The result shows that the entransy dissipation-based thermal resistance,not the exergy efficiency,characterizes the heat transfer performance of an evaporative cooling system,which provides a more suitable method for evaluating and analyzing the indirect cooling system.展开更多
文摘针对阻尼结构设计,利用拓扑优化技术研究了阻尼结构模态损耗因子最大化设计问题。采用密度法(Pseudo-density Method)和材料属性合理近似模型(Rational Approximation of Material Properties,RAMP)建立了以阻尼材料用量为约束条件、模态损耗因子最大化的阻尼板结构拓扑优化数学模型,并进行了灵敏度分析;利用优化准则法(Optimality criteria,OC),给出了阻尼结构拓扑优化设计方法和流程,得到了在一定阻尼材料用量下阻尼板结构的模态损耗因子最大的阻尼材料最优分布构形。相关算例结果表明该方法适合于阻尼结构的优化设计或轻量化设计。
基金supported by the National Natural Science Foundation of China (51006060)
文摘The wide application of evaporative cooling techniques in which the optimization criteria form the theoretical basis for improving evaporative cooling performance is essential for energy conservation and emission reduction.Based on exergy analysis and the entransy dissipation-based thermal resistance method,this contribution aims to investigate the effects of flow and area distributions in the optimization of the performance of indirect evaporative cooling systems.We first establish the relationships of exergy efficiency,entransy dissipation-based thermal resistance and cooling capacity of a typical indirect cooling system.Using the prescribed inlet parameters,the heat and mass transfer coefficients and the circulating water mass flow rate,we then numerically validate that when the cooling capacity reaches a maximum,the entransy dissipation-based thermal resistance falls to a minimum while the exergy efficiency is not at an extreme value.The result shows that the entransy dissipation-based thermal resistance,not the exergy efficiency,characterizes the heat transfer performance of an evaporative cooling system,which provides a more suitable method for evaluating and analyzing the indirect cooling system.
